In general, when a mobile communication terminal transmits UpLink (UL) data, there is a known trade-off relationship between time and energy needed to transmit an information bit. That is, transmission energy efficiency increases in proportion to a transmission time. There are various data transmission scheduling methods based on such a trade-off relationship. Examples of the methods include lazy scheduling and move right scheduling.
The known trade-off relationship between the time and energy needed to transmit the information bit is obtained under several theoretical assumptions. That is, the trade-off relationship is obtained without proper consideration of a characteristic of a power amplifier (see FIG. 1) included in the mobile communication terminal.
To know energy consumed by the mobile communication terminal, the trade-off relationship between the time and energy needed to transmit the information bit has conventionally been attained by using an output of a node Ptx 105 of the power amplifier under the assumption that energy obtained from a Direct Current (DC) voltage 103 is used to amplify a signal input through a node Pin 101 at a fixed efficiency below 1 and the amplified signal is output to the node Ptx 105.
However, since the power amplifier receives energy needed to amplify the signal from the DC voltage 103, energy used by the mobile communication terminal to transmit an actual signal is equivalent to energy provided to the power amplifier from the DC voltage 103. In addition, the power amplifier has a characteristic of a nonlinear efficiency, that is, amplification efficiency varies according to a range of a signal to be amplified, rather than a fixed efficiency.
Hence, there is a need for a method of performing UL scheduling by considering the trade-off relationship between the time and energy needed to transmit the information bit according to the characteristic of the power amplifier included in the mobile communication terminal.